Bullying in childhood is a growing American public concern, long-term adjustment heath related to serious problems for aggressors and victims. Among the most troubling findings from recent research is the claim that bullies are popular. If bullies are popular, children may be more likely to internalize positive messages about aggression and to tolerate or promote peer victimization. Widely-used anti-bullying programs tend to assume that bullies are unpopular and rejected by their nonaggressive peers. As a result, current antibullying programs do not identify bullies who are popular or provide these children with effective treatments. This investigation will provide a comprehensive evaluation of the "popular bully" hypothesis. The study aims to: (a) introduce new concepts and methods for assessing popularity, (b) detail the variety of relationships that bullies form with their peers, and (c) chart developmental trends in the relationship between bullying and popularity. The sample will consist of 600 third and fourth grade children attending eight ethnically diverse schools. This age group was selected because preadolescents are often passed by in favor of adolescents in major investigations of bullying, but the developmental origins of bullying lie in the middle childhood years if not before. Data will be collected through sociometric surveys, teacher information about participating children and their classroom social dynamics, and school demographic and disciplinary records. Three sets of research questions drive this investigation: (1) Is there more to popularity than likeability? Past research may have underestimated the popularity of bullies by overemphasizing likeability as opposed to being perceived as cool or influential. (2) Do bullies form relationships with nonaggressive children? Bullies are often portrayed as members of deviant peer groups, but popular bullies may form friendships and affiliate in groups with nonaggressive children. (3) Developmental questions are critical. Are bullies more or less likely to be popular as middle childhood proceeds? Do children who become more popular then bully more, or less? Do children who become bullies gain or lose popularity? The goal of this investigation is to understand how popularity and peer relationships can enhance bullying behavior. Careful attention will be paid to bullying within and between boys' and girls' groups. The long-term objective is to begin the process of building interventions that can be effective for bullies who are well-integrated into peer social life.